1. Field of the Invention
The present invention relates to a method of manufacturing an information display panel, in which at least one group of display media having optical reflectance and charge characteristics and consisting of at least one or more groups of particles, are sealed in a cell formed by partition walls between two substrates, at least one substrate being transparent, and, in which the display media, to which an electrostatic field is applied, are made to move so as to display information such as an image.
2. Description of Related Art
As an information display device substitutable for liquid crystal display (LCD), information display devices with the use of technology such as an electrophoresis method, an electro-chromic method, a thermal method, dichroic-particles-rotary method are proposed.
As for these information display devices, it is conceivable, as compared with LCD, as inexpensive visual display device of the next generation from a merit having wide field of vision close to normal printed matter, having smaller consumption, or having a memory function, and spreading out to a display for portable device and an electronic paper is expected. Recently, electrophoresis method is proposed that microencapsulate dispersion liquid made up with dispersion particles and coloration solution and dispose the liquid between faced substrates, and also it is expected.
However, in the electrophoresis method, there is a problem that a response rate is slow by the reason of viscosity resistance because the particles migrate among the electrophoresis solution. Further, there is a problem of lacking imaging repetition stability, because particles with high specific gravity of titanium oxide is scattered within solution of low specific gravity, it is easy to subside, difficult to maintain a stability of dispersion state. Even in the case of microencapsulating, cell size is diminished to a microcapsule level in order to make it hard to appear, however, an essential problem was not overcome at all.
Besides the electrophoresis method using behavior in the solution, recently, a method wherein electro-conductive particles and a charge transport layer are installed in a part of the substrate without using solution is proposed. [The Imaging Society of Japan “Japan Hardcopy '99” (Jul. 21-23, 1999) Transaction Pages 249-252] However, the structure becomes complicated because the charge transport layer and further a charge generation layer are to be arranged. In addition, it is difficult to constantly dissipate charges from the electro-conductive particles, and thus there is a drawback on the lack of stability during display rewriting.
As one method for overcoming the various problems mentioned above, an information display panel is known, in which at least one or more groups of display media having optical reflectance and charge characteristic, which are constituted by at least one of more groups of particles, are sealed between opposed two substrates, at least one substrate being transparent, and, in which the display media, to which an electrostatic field is applied, are made to move so as to display information such as an image.
In a method of manufacturing the information display panel mentioned above, as a method of filling the display media in the cell, it is conceivable that the display media are scattered from an upper portion of the cell so as to fill the display media in the cell. FIG. 24 is a schematic view explaining one known method of filling the display media. In FIG. 24, display media 56 are filled in a cell 54 by: setting a substrate 55, on which the cell 54 is formed by means of partition walls 53, at an under portion of a container 52 having a nozzle 51 at its upper portion; arranging a mask 57 on a top portion of the partition walls 53; and scattering the display media 56 from the nozzle 51. In the scattering method mentioned above, since a time necessary for filling is long, there is a drawback, especially when plural groups of the display media are to be filled in the cell, such that it takes a long time due to a repetition of the same filling step to the number of plural groups of the display media to be filled. In order to solve the problem mentioned above, it is conceivable that the display media a re filled in the cell by means of a squeegee-method, in which the display media are arranged on the substrate having the cell and a plate member called a squeegee is moved on the substrate. However, in this squeegee-method, there is a drawback such that a control of an area, to which the display media are to be filled, and a control of an amount of the display media to be filled are difficult.